Robert lundell



(No Model) v R. LUNDELL. BRUSH HOLDER FOR DYNAMO ELECTRIC MACHINES.

Patented July 6, 1897.

INVENTORZ WITNE By 111': A/zomey UNITED STATES PATENT OFFICE.

ROBERT LUNDELL, OF BROOKLYN, NEIV YORK, ASSIGNOR OF TlVO-TIIIRDS CONDUITAND INSULATIOI COMPANY, OF NEIV TO THE INTERIOR YORK, N. Y.

BRUSH-HOLDER FOR DYNAMO-ELECTRIC MACHINES.

SPECIFICATION forming part of Letters Patent No. 585,872, dated July 6,1897.

Application filed July 11, 1896. Serial No. 598,801. (No model.)

To all whont it may concern:

Be it known that I, ROBERT LUNDELL, a citizen of the United States,residing at Brook lyn, in the'county of Kings and State of New York,have made a new and useful Improvement in Holding and Adjusting Devicesfor the Com m u tator-Brushes of Dynamo-Electric Machines or ElectricMotors, of which the followingis a specification.

My invention relates particularly to improvements upon an inventiondescribed and claimed in a prior patent granted to me on the 26th day ofSeptember, 1893, and numbered 505,665; and it has for its objects,first, the construction of a brush holding and adjusting device whichwill prevent chattering of the brushes when the machine is running;second, the construction of a brush-holding device which will be adaptedto give substantially constant pressure of the brush upon the commutatorfor varying lengths of said brush as it wears away; third, the arrangement and adaption of such a brush-holding device for use with equalfacility whether the commutator be rotated in one direction or theother, and, fourth, the adaptation of abrushholder for brushes ofdifferent thickness.

In the brush-holding device described and claimed in my prior patentabove referred to there is arranged a yielding spring adapted to feedthe brush forward as it is worn away. I have discovered that with abrush-holder of that form however, chattering often occurs, andparticularly when the commutator is runnin gin a reverse direction fromthat for which it is normally set. WVith the type of device described inmy prior patent it was also impossible to render the pressure constantfor various lengths of brushes.

My present invention also contemplates this adjustable feature, and theespecial points of novelty and utility of my invention will be describedin the following specificationand particularly pointed outin the claimsat the end thereof.

Referring now to the drawings, Figure 1 is a plan View of my improvedbrush-holder. Fig. 2 is a longitudinal sectional view taken through Fig.1 on the line 2 2 and as seen looking at that figure from the bottomtoward the top of the drawing in the direction of the arrows, animaginary commutator being also shown rotating from right to left. Fig.3 is a side elevational view as seen looking at Fig. 1 from theleft-hand toward the right-hand side of the drawing, the adjustingdevices being removed and the invisible portions as seen from that viewbeing shown in dotted lines. Fig. 4 is a longitudinal sectional view ofFig. l on the line 4 t and as seen looking at that figure from thebottom toward the top of the drawing, this figure of the drawings alsoindicating an imaginary commutator rotating in the reverse directionfrom that shown in Fig. 1 and a diagrammatic view of the forces actingupon the brush when the machine is in motion.

Referring now to the drawings in detail, 11 represents a brnslrholdin gdevice adapted to sustain in a rectangular guideway a carbon brush Bwith its lower end resting upon a commutator O, 77/2 being therectangularshaped shank of the brush-holder, provided with the usualshoulder h and screw-threaded neck 72,3 for securing it (the holder) tothe brush-rockers in awell-known manner.

I1 is a laterally-extending yoke integral with the brush-holding part IIand provided at its rear end with an upwardly-extending portion H whichhas in turn a vertical slot h, said parts being adapted to secure theadjustable parts of my improved brush-holder.

A is an L-shaped metallic part having sufficient bearing against theinner face and top portion of the brush B to hold it firmly in positionin the rectangular guideway of the stationary part H. This part A isprovided with lugs or cars a, to which is pivoted bya pin 19 and anextension (I a cylindrical part D, adapted to sustain by a shoulder done end of a spiral spring S, d being a cylindrical neck adapted to movefreely within the inner surface 6 of a second pivoted portion E, securedby a pin c and extension e and lugs or cars g to an adjustable arm G,having a rectangular-shaped extension which is adapted to movevertically in the rectangular slot h in the upwardly-extendin g portionH The outer surface of the second pivoted portion E is screw-threadedand adapted to receive an adjusting-nut F, provided with a shoulder forbearing adjustably against the free end of the spring S.

w is a split washer, and T a screw-threaded adjusting-nut adapted tosecure the adjustable arm G at any desired height in the slot 7t, beinga split pin in the outer end of the screw-threaded extension g g forpreventing the absolute removal of the nut T.

The operation of myimproved brush-holder is as follows: The brush B isslipped in place in the rectangular guideway of the holder II, and theL-shaped adjustable holding device A is placed in the position shown inFigs. 1, 2, and l. The adjustable arm G is then pressed downward untilthe pressure of the parts gives to the brush the desired firmnessagainst the inner face of the holder H and downward pressure against thecommutator C. The set-nut T is then screwed firmly home against thesplit washer to, and the apparatus is ready for use. Should it bedesirable at any time, owing to the wear of the brush upon thecommutator, to give a further advancement to the holding device the nutl is simply turned to the right, so as to cause the spring S to act withthe required pressure upon the movable part D and hence through thepivotal part upon the adjustable holder A.

Should further advancement be required, owing to the wearing away of thelower end of the brush B, it is only necessary to release the set-screwT and give to the adjustable arm G a downward m ovem cut-,so as tomaintain the angular position of all of the adjustable parts in therelation fixed upon at the first setting of said parts, after which theset-nut T is firmly secured as before. It will be seen that through thisdouble adjustment of the parts G T, E F, and D A, I am enabled to giveto brushes of varying lengths a pressure upon the commutator which issubstantially constant and at the same time to avoid any possibility ofchattering.

In Fig. I have shown the operation of th device under the contingency ofa rotation of the commutator in a reverse direction from that shown inFig. 2, it being apparent from the parallelogram of forces illustratedby the letters a; and 3 and the normal frictional force due to theaction of the commutator indicated at .2 that the brush B can neverleave the inner surface of the stationary holding part II, therebyavoiding any possibility of chattering and also avoiding the evileffects of raised conmiuta-tor-bars. Vith this improved brush-holdingdevice I find it possible to utilize brushes of variable thickness andto enable one to use such brushes with substantially constant pressureupon the commutator and without any chatter whatever, no matter in whichdirection said commutator may be rotating.

My improved holding device may also be used in any place where it isdesired to conduct electricity from a stationary to a moving conductor,and vice versa, and my claims include all such uses.

Having thus described my invention, what I claim, and desire to secureby Letters Patent of the United States, is-

1. A commutator-brush holder provided with two sets of adjustingdevices, one of which sets of adjusting devices tends to give to thebrush downward pressure against the commutator and a lateral or sidepressure against the stationary part of the holder, and the other givesto all of said parts vertical adjustment so as to adapt the entirestructure for brushes of various lengths, substan tially as described.

2. A commutator-brush holder provided with a stationary guideway for thebrush and a movable part adapted to bear against the brush in twodirections, said movable part being pivotally secured to an adjustabledevice, one part of which is mechanically connected with the stationarypart of the holder, substantially as described.

3. A commutator-brush holder consisting of a stationary part and amovable part adapted to exert a pressure upon the brush in twodirections, in combination with adjustable means connecting said movablepart with the stationary part whereby the pressure may be varied asdesired, substantially as described.

I. A commutator-brush holder consisting of a stationary part providedwith a guideway for the brush, a movable part pivotally connected tospring-actuated adjusting mechanism, which adjusting mechanism is inturn secured to the stationary part, all of said parts being so arrangedthat the adjusting mechanism tends to give to the brush movement in twodirections, substantially as described.

5. A commutator-brush holder consisting of a stationary part providedwith a guideway for the brush, a movable part adapted to bear againstthe brush in two directions and pivotally secured to a spring-actuatedadjusting device which in turn is pivotally secured to a secondadjusting device having mechanical connection with the stationary partof the holder, substantially as described.

In testimony whereof I have hereunto subscribed my name this 30th day ofJune, 1896.

ROBERT LITNDELL.

\Vitnesses:

C. J. KIN'INER, M. M. ROBINSON.

